Outlet box with overlapped knockouts



Dec. 22, 1953 J, o so I 2,663,454

OUTLETBOX WITH OVERLAPPED KNOCKOUT Filed Jan. 30, 1950 Z Sheets-Sheet 1 INVEN TOR. OSCAR J 0/.s0/v

A T'TORNE Y6 Dec. 22, 1953 o. J. OLSON 2,663,454

OUTLET BOX WITH OVERLAPPED 'KNOCKOUT Filed Jan. 30, 1950 2 Sheets-Sheet 2 INVENTOR. 0504/? J OLSON Patented Dec. 22, 1953 OUTLET BOX WITH OVERLAPPED KNOCKOUTS Oscar J. Olson, Seattle, Wash.

Application January 30, 1950, Serial No. 141,241

9 Claims. (Cl. 220-27) Outlet boxes for connection to lighting fixtures, or for the support of switches, sockets, or like electrical elements, are liberally used in modern construction, and are normally set flush with the surface of the finished wall. Behind this wall are various structural elements, pipes, conduits, and the like, installed at different times, often by different workmen, which in the aggregate produce a maze of interlacing members each vying with the other for space behind the finish wall. Some lie close behind the wall, whereas others are thereby forced to a greater depth behind the wall. The result is that a conduit for electrical leads which must be connected to a given outlet box, must often be bent sharply and with some little accuracy, in a small space, and in order to get over or around some already installed member, and to lead its end to the proper spot in the wall of the outlet box where the knockout is located, for such outlet boxes are normally provided with side wall knockouts located at one depth only, inwardly from its open outer end, and the conduit must be connected there, or else must be goosenecked and connected through a knockout in the enclosed end wall of the outlet box, or the outlet box must be increased in depth by the addition of an extension, which latter is costly, and either of which adds to the depth necessary behind the finish wall, which sometimes is a critical dimension.

It is the object of the present invention to provide an outlet box so designed that conduits may be led to and from its side walls by whatever is the most direct path, having regard to the avoidance of structural elements and the like creating obstructions, so that the bending or offsetting of the conduits, particularly within close quarters, is avoided to the highest possible degree, the ease of connection of the conduits to the outlet box is greatly improved, the possibility of dislocation of the outlet box is lessened, and the need for greater depth purely for purposes of connecting conduits to the outlet boxes is eliminated.

Likewise it is an object of the present invention to provide an outlet box and a wall assembly including the same, of a design having the maximum in simplicity, and at no appreciable cost in addition to normal outlet boxes and assemblies incorporating the same, and indeed at less cost than the normal assembly if an extension box has to be employed.

These and other objects of the present invention will become more clearly apparent as this specification progresses.

The features which distinguish the present invention are shown in a typical form and arrangement in the accompanying drawings, and will be more fully disclosed in this specification and in the claims which terminate the same.

In the accompanying drawings the invention is shown, as has been indicated, in a single typical form, but it will be realized that the principles of the invention may be incorporated in various other forms and arrangements, and that in particular the outlet box. illustrated is a generally standard octagonal box, but that there are a number of other standard forms, any of which may incorporate the principles of thepresent invention, as will shortly be made clear.

Figure l is an isometric view from above, or more generally speaking fromthe rear of a finish wall or a ceiling of 'the suspended type, showing my improved outlet box, assembled in operative relationship to such finish wall and to the structural elements supporting the same.

Figure 2' is a side elevation of such an outlet box in a presently preferred form of arrangement such as incorporates the present invention, and

Figure 3 is an enlarged sectional view through a,

wall of the same generally at the line 3-3 of Figure 2. Y j

Figure dis a side elevational view similar to Figure 2, showing a slightly modified arrangement.

As has been indicated above, the invention in Figure 1 is shown in assembled relationship above or to the rear of a ceiling 9, which is a finish wall of one type, and which is directly supported upon expanded metal lath 90. The lath is wired to or otherwise supported from structural elements such as the channel 9i, as is indicated at 92, there being a number of such channels in at fairly close spacing in direct contact with the rear side of the metal lath 96. In turn these channels 9| are crossed by and connected to heavier channels 93, by wire ties as indicated at 94, hence the, channels 83 are spaced from the rear side of the metal lath by the depth of the channels 9!. The channels 93 themselves being of greater depththan the channels "9| obstruct quite materially the space behind the wall 9. The elements 93 in a vertical or side wall might be the studs or might be carried bystuds, or secured to furring strips. In a ceiling the entire assembly is usually suspended from above by the wires 95.

The outlet box I, with exceptions that will be pointed out hereinafter, is or may be of any standardjshape or size. The one chosen for: illustrationis'a standard octagonal box of some appreciable depth, sufilcient that its outer edge In may lie flush with the inside or forward face of the finish wall 9, as is customary, and extending to the rear of the finish wall, that is, behind the metal lath 90, to an appreciable depth. It is shown as provided with the conventional knockouts H in its closed end wall, and is supported by a strap 96 extending between structural elements suchas .the channeL93'fand-a similar channel spaced therefrom, "or; in anyfno'rinal manner.

Thus supported and located, it is obvious that from one direction th channels 91, somewhat obstruct access to a particular locatiori'ir'r the .side:

wall of the outlet box I, such as in earlier outlet boxes would be the location of the. knockout,. and from another direction the channels 93 also obstruct access to the box l,'"butat"adifferent depth or level. Both the conduits 2| and,- 22.inatended for connection to;the outlet box I would have to, bebentorofiset sharply if the knockouts in the side walls ofj'the' outletboxwere atijone location and. one only, as .is I. normally the. case. Moreover if the. problem .of access .of .thepondiiit to the outlet box,becomplicatedjby.water pipes, other electrical conduits, aircductspor the like, all of which areg rour'red in ,thisspecification under the general term structural,elements, it may be extremely jdiificult .to'. connect." the conduits properly to the outletbox, 'andlyet the/latter must be located at the, designated .spot', in" accordance with thearchitectsplans;

According to the ,preser'rtinvention, in at least one and preierab1y-.in;each of the sidewalls I2 which are to, have .jknockouts, aplurem 0f circle,A ,at...the, center; of .the ,circle TB} and .if a

fourth. or. additional circle suchasljis employed, the. circle;D. intersectslthe circle .0, andis tangent to. the {circle B at.. the. center of .theicircle- CT. The result is a straight alignment of the ,several. knockouts 7 formed- ,by these circles one being locatedlnear ,the, open. end [0 loirlfth'e goutle't' ,box. and the last being located nearer its closed lend While a, straightlinearran ement is. preferred the invention;'is .,,notl .to be. construedjas limited.

thereto," for. any-other jconyenientgrelative .Iover: lapping arrangement which;accomplishesithe..end in view is within-the present..invention.

The mannerof forming theseknockouts. isnot important itself... Normally they. Will'lbefformed as knockouts have heretofore heenlfor'medjname j ly by punching inoroifsettingithe .p ane. ot-the metal within the several circlestofracture' the metal substantially entirely about th circle, bi1t leaving ordinarily, a ,retaining tongue J3 to. s p: plement .,the. marginal. retention. jin supporting each such knockout, However in Jthe overlapped a r how or xam l ii 2fa p tcircular portion .ga,. .ofv ,tne area lw'i hanji the circle i c m ein i h-the sidewa ll' s i he e e with. each a of, thebther ,circle'a as. at b ,l', 112, e I '.I 0 2 etc whereas vthe .len'ticular portionsi'obrbc, cd,,'of t ea a hineg h scheme-whichacumen to another. ;circle,} -,a1:e nptcomarginal witntm sidewall i2 itself but. are independent thereof, iise n this mew comarginal areas a, bl, b2, 1!, etc. be retained by the tongues I3 but that the retention of the further offset lenticular areas ab, bc, cd common to two circles be merely by means of their marginal retention along the lines of fracture of the metal that defines these areas. At the same time, as in Figure 4, it is within the scope of the invention to provide additional tongues such as I3a whereby these'common lenticular areas ab,- bc, cd are secured" by the additional tongues to certain of the comarginal part-circular areas, as a, 02, d, to

' be' supported thus from the latter.

Whenever in installing such an outlet box it is found that" one'of the conduits 2| would naturally comeat a particular level in avoiding a structural elementsuch as the channel 9|, the knockout most nearly inline with the conduit would be knocked out'in-the normal way, and all others would remain in place, and in consequence the conduit 2| could be connected to the box with little or no offsetting or bending of the Conduit. Likewise the conduit 22, in running under or outwardly of the channel 93, would naturally reach the outlet box at a somewhat different level, and here again the knockoutimost nearly in line with the conduit 22 would'be knocked out in the normalway, In each case'thecoupling element 3 would connect upv the end of the conduit and the outlet box and substantially no deformation of the conduit for the purpose'ofl connection would be required. In otherrwords; the'point of con.- nection of the conduitfis independent of'one particular or arbitrary location of a knockout.

The present invention is to be distinguished from those known arrangements whereinknockouts are providedin multiple, one wholly within another and concentrically, or eccentrically arranged, .prir'narilyfor the purpose of connecting thenfperhaps a reducerw'ould' be required ex-,

ternallyof ithelmockout box, if a smaller coniduit is' .to be connected. Thepresentlinventionj isflconcerned with the connection of the conduit with no particular 'or arbitrarily located point inth'e wallof the outlet box, but ratherat'any depthffrfom the open endwherje the co'nduits end happensto come, and with the knockout provided in that 'wall at such apoint, or so close thereto that bending is unnecessary. V

As aresult of th present invention, extension boxes arenot n'eeded for the purposeof.fricfilitat ing connection, and the s'implicity'of installation of...the-outlet.boxes and Ithe'con'nection of the conduitstheretogreatly lessens the cost of installation and improves thequality thereof.

I claimasmy invention:

1. An electrical' outlet box. open at one end, and having enclosing side walls, one 'such wall at. least. being fractured about themargins ofa pluralityeof substantially, circular areas, to constitute .abeyantknockcuts', at leastone of said areas overlapping another such area in a lenticular areawhich is commonftc .each'knockout;

ZLfAnelectrical outlet box as inclaim L'Wherein the centers of the circular areasare arranged along a common longitudinallydirected axis.

3. .AnselectricalToutletabox a claim 1 including Iatvle'astl "three circularl areas and two Separate and "non-coinc dent leiiticulari areas,

arranged along a common, longitudinally directed axis.

4. An electrical outlet box as in claim 1, wherein the fractured side wall, the circular areas, and the lenticular area or areas are disposed each in its individual plane, non-coincident with the plane of its comarginal areas.

5. An electrical outlet box as in claim 4, wherein each circular area, outside its lenticular area, is secured to the comarginal wall area by a frangible but nonfractured tongue.

6. An electrical outlet box as defined in claim 5, characterized in that the entire margins of the lenticular area or areas are substantially completely fractured, but are retained in place by their marginal resistance to displacement relative to those portions of the circular areas which are comarginal with the wall.

7. An electrical outlet box as defined in claim 5, characterized in that the marginally fracarranged in a pattern such that two of the circles are mutually tangent, and a third circle encloses and is centered at the point of tangency.

9. An electrical outlet box as in claim 8, wherein at least one additional wall, adjacent the fractured wall first mentioned, is similarly fractured in a like pattern of at least three successively overlap-ping circles, but with the centers of the terminal circles displaced longitudinally of the box with relation to the location of the centers of the terminal circles in the first-mentioned side wall.

OSCAR J. OLSON.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 784,555 Fountain Mar. 14, 1905 977,643 Le Manquais Dec. 6, 1910 1,215,249 Burns Feb. 6, 1917 1,608,621 Sachs Nov. 30, 1926 1,813,331 Wadworth July 7, 1931 1,950,523 Severn Mar. 13, 1934 2,240,187 Kingdom et a1. Apr. 29, 1941 2,291,107 Rybolt July 28, 1942 2,297,862 Bachmann Oct. 6, 1942' 

